Devices have become very popular for self-administration of certain drugs such as insulin or apomorphine by patients.
A conventional device of this type is known e.g. from US 2005/0137571 A1. This device has a casing divided into front and rear portions which form front and rear parts, respectively, of a cavity in which a drug container is accommodated, and which can be taken apart in order to replace the drug container when empty.
Since the machinery needed for producing the drug containers and for filling them in a sterile manner is expensive, pharmaceutics manufacturers tend to use a same type of drug container for different drugs or for different preparations of a same drug.
If a patient uses such different drugs or different preparations, he might inadvertently replace an empty drug container by a container of a different drug or a different preparation, and consequently administer to himself a wrong dose of a required drug or even the wrong drug.